The Manhattan studio, run like a “prison-style boot camp”, offers personal training by day, and boutique group workouts — starting at $30 a session — by night.

The gym attracts hundreds of clients, and offers dozens of group classes per week. Just like in a prison, training focuses on using just body weight, including pull-ups, dips, and push-ups.

And, to add to the authenticity, nearly all the trainers at ConBody have once been imprisoned. The rest grew up with a similar lifestyle.

“My mission is to hire as many formerly incarcerated people as possible to teach fitness classes,” founder Coss Marte, 31, said. "I've seen the struggle of coming home."

Marte told InsideEdition.com he began ConBody inspired by the difficulties he faced when he was released from prison three years ago.

“The first job I received was probably two months out,” Marte said, “for $8 an hour, scrubbing toilets at a hotel. Not even paying taxes — it was off the books.”

Despite having once been heavily involved with a major drug delivery service in New York’s Lower East Side, being in and out of prison since he was 13 years old, and being ultimately charged as a drug kingpin when he was 23, Marte said his time behind bars changed him for the better.

Unfortunately, he had a hard time proving it to employers.

“I applied to hundreds of jobs,” he explained “The doors were closed in my face because I had three felonies. I wanted a second chance. I knew I was a changed person, and nobody was giving me that opportunity.”

Having had experience training fellow inmates during his time behind bars, Marte said he started leading group boot camps in public parks, spreading the word using no resources except his own charisma.

“I would wake up in the morning, and work out in the park,” he explained. “I started telling people I knew around the neighborhood first, [then] I was going after all the girls wearing Lululemon and telling them I’m doing this prison-style boot camp. I attracted people, and it started growing from there.”

Marte said he discovered his passion in training when he was locked up at 19 years old. He was facing three years in prison, but ended up only doing one year when he agreed to join the Shock Incarceration Program, a correctional boot camp-style alternative sometimes offered to non-violent offenders.

“It’s run by ex-marines,” he explained. “You wake up at 5 in the morning, shower, brush your teeth, make your bed, and you have to be ready in 8 minutes – shaved, clothes on, everything. Then, you work out for about an hour and a half.”

What he learned during the program would soon become part of the inspiration behind ConBody.

The second half, he explained, was inspired by inmates serving long sentences, who built up a tolerance to heavier weights and more intense work out routines over the years.

“The way we work out in there is probably most extreme. It was just pushing yourself to the limit,” he said. “They lock you in the shack – it was like this cage in the prison yard – for two hours, and you had access to weights. People were bench pressing 400 pounds, squatting 600 pounds, and when you go to the gym today, you see people messing around with 30 pounds. Over there, they took it to the next level.”

He left the Shock Incarceration Program his fittest self, but soon fell back into unhealthy habits, which developed into high blood pressure and high cholesterol.

When Marte landed himself in prison again in 2009, he lost 70 pounds by doing laps around the yard, and coming up with routines that could be performed in his 9-foot-by-6-foot cell, upon doctor’s recommendations.

Marte then went on to help other inmates get into shape as well, but credits his spiritual awakening in solitary confinement for his dedication to pursuing a new lifestyle in a legitimate industry.

“I was still selling drugs in prison, still messing around with gangs and all this crazy stuff,” Marte explained. “I didn’t think what I was doing was wrong — I just thought it was the lifestyle.”

Marte said he was just weeks from being released when he was 26, but ended up getting thrown into solitary confinement and having another year added to his sentence due to a misunderstanding.

“I was devastated," he said. "I thought I was coming home. My family was waiting for me. My son, who was just 6 years old at the time — I told him I was coming home."

He said he was alone with nothing but a bible, so he started reading.

"It really woke me up,” Marte said. “I started praying for the first time, and I asked God how I can get back to society."

He eventually thought to his passion for training, and came up with the idea for ConBody, which he planned to put into action when he was finally released.

With the help and a financial grant from Defy Ventures, a non-profit run along the motto that former criminal leaders have the skills to help them succeed as legal entrepreneurs, Marte was able to grow his influence, and eventually return to the Lower East Side, not as a felon, but as a businessman.

Sultan Malik, 36, ConBody's vice president, recalled the first time he met Coss Marte three years ago, months after his own release from prison.

“I’m not telling this guy anything [but] he looked at me, and he gave me that Coss signature look I’ve come to know,” Malik said, laughing.

Malik told InsideEdition.com he had already started training private clients within days after he was released from prison, but a successful meeting with Marte helped him channel his “assertiveness, aggressiveness, and sureness” of himself into a budding career in the legitimate sphere.

“They always say there’s a fine line that separates the street life from corporate life,” he explained. “Hostile takeover in the street — they mean weapons. In the corporate world, there are hostile takeovers, just done with pens."

Malik said he spent 14 years behind bars, seven of which in solitary confinement, after he was charged with attempted robbery and attempted assault.

“When I went in, I had a very cloudy, limited perspective on life,” he said.

But his worldview grew as his eyes were opened to racial inequality.

“I didn’t want to be a gangster anymore," he explained. "It was played out. It was corny to me. I just wanted to stop, and break the cycle for me and my family, and perhaps do the same for others."

During his stint behind bars, Malik said he spent most of his time exercising, but it wasn’t until a friend and inmate introduced him to the science behind working out that he really became interested in fitness.

When he was released in May 2014, Malik said he went right to work on making a name for himself, despite not knowing where to start.

“There’s the old saying 'fake it ‘till you make it,’” he said. “They asked me, ‘What do you do? You look like a trainer,’ and I’m like, ‘Yeah, that’s what I do. I’m a trainer.’”